Telephone-exchange apparatus.



E. E. YAXLEY.

TELEPHONE EXCHANGE APPARATUS. APPLICATION FILED SEPT. se, 1905.

905,619.` l Imtentedl De0.'1,19os.

llllllml UNITED sTATEs PATENT oEErcE.

ERNEST E. YAXLEY, OF CHICAGO, ILLINOIS, ASSIGNOR TO MONARCH TELEPHONE MANU- FAGTURING CO., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE-EXCHANGE APPARATUS.

Specification of Letters Patent.

Patented Dec. l, 1908.

To all whom it may concern.'

Be it known that I, ERNEST E. YAXLEY, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone-Exchange Apparatus, of whichthe following is a full, clear,

concise, and eXact description, reference being had to the accompanying drawings, forming a part .of this specification.

My invention relates to electro-magnets, and is of particular utility in connection with telephone switch-boards, the invention having several features that particularly relate to switch-board practice.

As my invention is of particular service in connection with telephone practice, I will particularly describe the same in connection with such practice, though I do not wish to be limited in all embodiments of the invention to this adaptation thereof.

The electro-magnet of my invention is highly serviceable in the construction of annunciators used at exchanges and electromagnets possessing certain features of the invention are of particular utility in the construction of line indicators of party tele hone lines. In party line practice, the win ing of a line indicator receives a comparatively large amount of current when connected with short party lines and will operate positively, but which may not cause distinct slgnals corresponding to the number of rings given by a subscriber, the amount of current being so great that the armature of the indicator will not always respond quickly enough to each impulse. If the line indicator is so wound and constructed as to operate properly on such a line, it may not be sensitive enough for use on a long and heavily loaded line. If the resistance of the coils is cut down to suit the long line, the eectiveness of the talking circuit may be impaired. I provide a very effective spring adjustment for the armature of the line indicator, which, while serviceable in other connections, is particularly serviceable in connection with party line practice. On a lightly loaded line where the line indicator` or annunciator receives considerable current, the lspring pressure is made properly large to increase the work to be performed by this current, whereby the operation of the armature is made quick and sharp. On a heavily loaded line, the spring pressure is reduced, so that the consequently reduced current may operate the armature with the same effectiveness as secured by the previous adjustment. In practicing this feature of `my invention, an adjustable spring mechanism is disposed to the rear of the armature of the indicator and this spring mechanism referably includes a spiral spring that is ibcated within a bore extending longitudi nally of the core of the magnet. One end of this spiral or coiled spring is preferably directly engaged with the rear face of the armature, that face immediately opposing the pole of the magnet, while the inner end of the s ring is preferably engaged by an adjusta le plunger, which plunger is desirably positioned by means of a screw passing through the head of the magnet and engaging the plunger. By turning this screw in one direction, the plunger is advanced against the force ofthe spring to increase the pressure upon the armature, While a reverse movement of the screw permits the spring to eXpand,f thereby reducing the spring pressure upon the armature.

Another feature of rn invention relates to the construction of an eIbctro-magnet wherein the spool of wire is removably contained in a tube. Hitherto it has been the practice to pass screws through the heads of these spools and into threaded recesses in the tubes, to secure the tubes and spools together. In the device of my invention, these screws may be eliminated, as I am enabled to effect mechanical engagement of the spool with the tube or shell (which tube or shell is preferably composed of soft iron to prevent leakage and induction between neighboring lines) by a turning movement of one with respect to the other, and to effect a disengagement between these parts, by a reverse movement of the spool with respect to the shell, so that the spool may readily be placed and locked within the shell and may readily be unlocked and Withdrawn from the shell. To this end, the spool is provided with one element of a locking device and the shell is provided with a complemental locking element. In the preferred embodiment of the invention, the element provided upon `the spool is in the form of a pin, while the element provided upon the shell is in the form of a bayonet catch, preferably constructed by providing a right-angular slot within that end of the shell contiguous to the head of the spool. I preferably supplement the locking mechanism llil above described by an instrumentality that serves to prevent the rotation of the spool in such a direction as to bring about its disengagement from the containing shell, this instrumentality desirably residing in a pivoted hook that may be swung into and out of engagement with the shank of a pin or screw., a screw being preferred as it may be driven to securely engage the hook. There are preferably two such hooks and screws provided, as they preferably serve to convey the current to the spool or magnet Winding, the said screws engaging the hooks desirably constituting the terminals of said winding and being preferably placed upon the rear face of the head of the spool, which head is desirably of larger diameter than the bore of the shell, so that the extent to which the spool may be inserted within the shell is determined.

The electro-magnet of my invention is well adapted for telephone practice, for in such practice it may constitute a part of an annunciator which has ready association with a line or answering jack, which combination forms the subject matter of my division of this application, Serial No. 327 ,221, iiled July 21, 1906.

I will explain my invention more fully by reference to the accompanying drawing, showing the preferred embodiment thereof, in which- Figure 1 is a longitudinal view, mainly in section, of a structure constructed in accordance with the preferred embodiment of my invention. Figs. 2 and 3 are views showing so much of the mechanism that appears in end view as is necessary to an understanding of the invention, Fig. 2 showing the fastening hooks in position, while Fig. 3 shows said hooks in an alternative position.A Certain elements are omitted from Figs. 2 and 3 in order that certain novel features may more clearly appear. Fig. 4 is a plan view of the rear portion of the magnet structure, parts being broken away clearly to reveal certain details of construction.

Like parts are indicated by similar characters of reference throughout the different figures.

The tubular shell c is desirably composed of magnetic material and is preferably cylindrical, as is desired in telephone practice. The armature b is in this instance pivoted at c and in its normal or unattgracted position causes the catch d to engage the shutter or drop e, as is well understood with reference to this class of apparatus, certain features auxiliary to the shutter being indicated but whose functions are so well known that a description thereof is not required. The shell a contains the spool or windingfwound upon a core g, which is preferably of iron, so that it may take part in effecting the attraction of the armature b when the winding f is ineluded in circuit. rIhe spool is provided with heads h-fi, the head h being contained within the shell and serving to position the same axially with respect to the cylinder a, while the head t' is upon the exterior of the shell and limits the extent to which the spool may be inserted therein. nates in a core-head 7c that fills the rear end of the shell and which coperates with the head h to maintain the spool in firm position within the shell,

As indicated most clearly in Fig. 4, the shell a is provided with the formation of a locking element, a bayonet slot Z being preferably formed in said shell to constitute such element. panion locking element, in this instance in the form of a pin m (having fixed mounting upon the spool structure) that is engaged with said bayonet slot first by longitudinally moving the spoolf so that the pin m will pass through the portion of the bayonet slot that is longitudinal of the shell a, whereafter a turning movement of said spool toward the right will engage the said pin with the trans verse portion of the bayonet slot. The pin m prevents withdrawal of the spool when in this position, which is shown in Fig. 4. In order to prevent the spool from rotating in the reverse direction, I provide one or two fastening devices, such as the elements n o, that engage projections carried by the spool, such as the elements pf-g. The elements n-o are preferably in the form of hooks that are pivoted at rtl-o1, which pivotal places The core g termi-` rIhe spool is provided with a com- .j

lso constitute terminal attachments for the springs or contacts ##02 of the jack r. The elements p--q are preferably in the form of screws that are carried in the metallic blocks g1-p1, constitutin terminals of the winding of the magnet spoo The hook or free ends of the elements n-o are adapted to be interposed between the heads of the screws p-g, whereafter said screws may be tightened down upon said hook ends, whereby the annunciator or indicator winding is placed in electrical connection with the jack and the line connected with the jack. In the construction shown, the element o2 is a back contact that is separated from the spring o3 when a plug is thrust within the jack, the invention, however, not being limited to this precise arrangement of the jack and indicator winding. It will be seen that when the elements 'rt-o are thus placed in engagement with the screws p-q, that the spooIf cannot be rotated to withdraw the pin m from the engaging bayonet slot.

The core g of the indicator is provided with an axial bore s, within which there is disposed a spring t, which spring is preferably a coiled spring and which projects beyond the coreelement g to engage the armature b, to impose a load upon said armature suited to the strength 0f the magnet to secure the proper operation of the armature. The force of this depresses the spring t, thereby increasing the load upon the armature b, making the strucl ture better adapted to operate under the inluence of heavier currents, that is, for example, on shorter lines. If the current in the winding is not strong enough to properly attract the armature b with a given adjustment of the spring t, the screw u may be withdrawn to an extent that will properly reduce the pressure of the spring t upon said armature.

A portion of the structure herein described and shown relating to the combination of the line-jack with the indicator, forms the subject matter of my aforesaid divisional application Serial No. 327,221, led July 2l, 1906.

I use the term spring in the sense of a cushion to be operated upon by the armature as a cushion when the armature is attracted, the spring imposing a load upon the armature.

While I have herein shown and particularly described the preferred embodiment of my invention, I do not wish to be limited to the precise construction shown, as it is obvious that changes therein may be made without departing from the spirit oi' my invention, but,

Having thus described my invention, I claim as new and desire to secure by Letters- Patent:

1. An annunciator having an electromagnet including a shell portion, the spool portion containable within the shell portion, a locking device havino' one locking member provided upon the she l portion and a companion locking member provided upon the spool portion, said members being adapted for locking connection by rotation of the spool with respect to the shell, and a fastening device for preventing the rotation of the spool with res ect to the shell when the members of saic locking device are engaged.

2. An annunciator having an electromagnet includin a shell portion, the spool portion containa le within the shell portion, a locking device havin one locking member provide u on the she l portion and a companion loc ing member provided upon the spool portion, said locking device being in tie form of a bayonet catch, the bayonet slot being formed in the shell while the pin for engagement with said slot is carried upon the magnet spool, and a fastening device for preventing the rotation of the spool With re spect to the shell when the members of said locking device are engaged:

3. An annunciator having an electromagnet including a shell portion, the spool portion containable within the shell portion, a lockin device having one locking member providerI upon the she l portion and a companion locking member provided upon the spool portion, said locking device being in t e form of a bayonet catch, and a fastening device for preventing the rotation of the spool with respect to the shell when the members of said locking device are engaged.

4. An annunciator having an electromagnet having a pivoted armature and a spring engaging the armature, the core portion ofthe magnet being provided with a bore within which said spring is dis osed, and an adjusting device working witliin said bore for determining the force of said spring, said adjusting device including a plunger in the bore and a screw for moving the plunger within the bore against the force of said spring.

5. An annunciator having an electromagnet having a pivoted armature and a spring engaging the armature, the core ortion of the magnet being provided wit a bore within which said spring is disposed, and an adjusting device workin within said bore for determining the force o? said spring.

In witness whereof, I hereunto subscribe my name this twenty third day of September A. D., 1905.

ERNEST E. YAXLEY.

Witnesses:

G. L. CRAGG, LEON STROH. 

